You could always run two circuits rather than one circuit with
paralleled conductors.
If I did that, I would run two 240 volt circuits and put the lighting
on one of them. Trying to balance the 120 volt loads so there is not a
lot of current in the neutral. That way if you pop the circuit breaker
from a heavy tool load you won't be in the dark.

The voltage drop is something you can compensate for with a buck boost
transformer. It is somewhat of a problem with loads that vary. I
would use circuit breakers sized to protect the wiring and if you want
to guard against low voltage use a panel in you shop with smaller
breakers.


Dan